Executive Summay of Project Goals

Executive Summary of Project goals

Project goals

Our goal is to develop advanced simulation software, utilizing extreme parallelism and based upon a
first-principles kinetic approach, to address the challenges associated with
understanding the edge region of magnetically confined plasmas. This work is
relevant to existing magnetic fusion experiments and essential for
next-generation burning plasma experiments such as ITER. The success of ITER is
critically dependent upon sustained high confinement (H-mode) operation, which
requires an edge pedestal of sufficient height for good core plasma confinement
without producing deleterious large-scale, edge-localized instabilities. The
plasma edge presents a set of multi-physics, multi-scale problems involving a
separatrix and complex 3D magnetic geometry. Perhaps the greatest computational
challenge is the lack of scale separation – temporal scales for drift waves,
Alfvén waves, and ELM dynamics, for example, have strong overlap. Similar
overlap occurs in the spatial scales for the ion poloidal gyro-radius, drift
wave, and plasma pedestal width. Microturbulence and large-scale neoclassical
dynamics self-organize together nonlinearly. The traditional approach of
separating fusion problems into weakly interacting spatial or temporal domains
clearly breaks down in the edge. A full kinetic model (total-f non-perturbative model) must be applied to understand and
predict the edge physics including non-equilibrium thermodynamic issues arising
from the magnetic topology (e.g., the
open field lines producing a spatially sensitive velocity hole), plasma wall
interactions, neutral and atomic physics.